Linear motor of moving-coil type

Abstract

A linear motor of moving-coil type is disclosed, in which a multi-phase moving coil includes a plurality of flat coil units each not wider than the longitudinal length of a permanent magnet making up a stationary part divided by the number of coil phases, the flat coil units being arranged successively in the same plane with central parts not adjacently overlaid one on the other. The central parts of the moving flat coil units have a thickness equivalent to a single phase in spite of the multiple phases of the moving coil. Thus a great electromagnetic force is generated, and at the same time a high propulsive force is obtained with the magnetic flux density not reduced in the gap accomodating one phase of coils alone.

We claim: 
     
       1. A linear motor of moving-coil type comprising: a stationary part including a pair of magnet bands extending in a longitudinal direction disposed in parallel relationship, each band having a plurality of permanent magnets having a width dimension as measured in said longitudinal direction with the magnetic poles thereof alternately reversed, said magnet bands being placed in opposed relations with each other with the magnetic poles thereof arranged in opposite polarities to each other, said magnet bands having a uniform gap therebetween; and   a moving part including a multi-phase moving coil having a plurality of flat coil units arranged in said gap, the dimension of a central part of the coil unit in the longitudinal direction of the magnetic band of the multi-phase moving coil being not greater than the width of one of said permanent magnets divided by the number of coil phases in said multi-phase moving coil, there being provided a plurality of the flat coil units each with central parts having the same width, said flat coil units being arranged successively in such a manner than the central parts thereof lie along a common central plane and are not laid one on the other in said gap, the flat coil units having a total dimension as measured in said longitudinal direction equivalent to an appropriate number of blocks each including two magnets,   said flat coil units being arranged for movement in the gap in the longitudinal direction of the magnetic band thereby to make up a moving flat coil with adjacent coil units having a thickness equivalent to the thickness of a single phase coil unit, said moving flat coil being fixed on a table.   
     
     
       2. A linear motor of moving-coil type according to claim 1, wherein said moving flat coil units are arranged back-to-back with an insulating member therebetween, thereby forming two coil unit parts each corresponding to a single phase. 
     
     
       3. A linear motor of moving-coil type according to claim 1, wherein the total length of the moving flat coil units along the width thereof is equivalent to the length of two blocks. 
     
     
       4. A linear motor of moving-coil type according to claim 1, wherein the ends of the moving flat coil units of respective phases are laid one on the other. 
     
     
       5. A linear motor of moving-coil type according to claim 1, wherein the ends of the moving flat coil units of respective phases are placed one over the other in spaced relationship with each other. 
     
     
       6. A linear motor of moving-coil type according to claim 1, wherein a fixing member for fixing the moving flat coil units on a moving table is made of a heat radiating material. 
     
     
       7. A linear motor of moving-coil type according to claim 6, wherein the outer peripheral part of the fixing member of the heat radiating material is formed with a multiplicity of fins. 
     
     
       8. A linear motor of moving-coil type according to claim 6, wherein the ends of the moving flat coil units are filled with a heat-conductive resin and the fixing member of the heat radiating material is bonded. 
     
     
       9. A linear motor of moving-coil type comprising: a stationary part including a pair of side yokes, a plurality of permanent magnets arranged in longitudinal direction with adjacent magnets thereof in opposite polarities thereby to make up a stationary member of a magnet band, a pair of said stationary members being placed in opposed relations with each other with magnetic polarities alternately opposed to each other, said permanent magnet bands being arranged in a manner to form a longitudinal gap therebetween, the side yokes having the ends and the lower parts thereof fixed on end yokes and a plate, the side yokes having rails thereon; and   a moving part including a multi-phase moving coil having a plurality of flat coil units arranged in said gap, each flat coil unit having a width not more than the size of each permanent magnet as measured in said longitudinal direction divided by the number of coil phases, said flat coil units being arranged in a plane successively in such a manner that the central parts thereof may not be laid one on the other, the flat coil units having a total dimension as measured in said longitudinal direction equivalent to an appropriate number of blocks each including two magnets, said flat coil units being arranged in the gap thereby to make up a moving flat coil with adjacent coil units having a thickness equivalent to the thickness of a single phase coil unit, said moving flat coil being fixed on a table through a fixing member, said moving part further including sliders on the sides of said table, said sliders being placed on said rails.